Okinawa Island is the largest of the Okinawa Islands and the Ryukyu (Nansei) Islands of Japan in the Kyushu region. It is the smallest and least populated of the five main islands of Japan. The island is approximately 106 kilometres (66 mi) long, an average 11 kilometres (7 mi) wide, and has an area of 1,206.98 square kilometers (466.02 sq mi). It is roughly 640 kilometres (400 mi) south of the main island of Kyushu and the rest of Japan. It is 500 km (300 mi) north of Taiwan. The total population of Okinawa Island is 1.4 million.

Singapore is a sovereign island city-state in maritime Southeast Asia. It lies off the southern tip of the Malay Peninsula, bordering the Straits of Malacca to the west, the Riau Islands to the south, and the South China Sea to the east. The country's territory is composed of one main island and 63 satellite islands and islets. It has the second greatest population density in the world.